﻿create table [dbo].[friendship]
(
	[user_1_id] int not null, 
    [user_2_id] int not null, 
	foreign key ([user_1_id]) references [dbo].[user]([user_id]),
	foreign key ([user_2_id]) references [dbo].[user]([user_id]),
    primary key ([user_1_id], [user_2_id])
)
